Conventionally, a thin laminated piezoelectric element is known as a piezoelectric element. In such a piezoelectric element, electrode layers such as a surface electrode or an internal electrode are electrically connected via a side electrode or a through hole conductor penetrating a piezoelectric layer.
The side electrode is generally provided through baking, sputtering, deposition, or the like on a side surface of an element body, but such a side electrode is easily damaged or deteriorates due to external factors since the side electrode is exposed to the outside. On the other hand, since the through hole conductor is located inside the element body, the through hole conductor has high resistance to the external factors. Japanese Unexamined Patent Publication No. 2004-207340 (Cited reference 1) discloses an actuator in which electrodes are electrically connected via a through hole conductor.